Update documentation to make it clear that the content of the efs directory is shared will all users of the Fornax Science Console

[vandesai1]

The relevant section is here:

https://nasa-fornax.github.io/fornax-demo-notebooks/documentation/README.html#how-can-i-upload-my-own-data-for-use-with-compute-provided-by-the-fornax-science-console